Threaded grinding wheels are used for the continuous generation grinding of gear wheels. Because the grinding wheel is subjected to natural wear and tear during this process, it has to be dressed from time to time. In the dressing process, material is machined off the flanks of the thread (or the threads) of the grinding wheel which narrows the tip area of the thread (or the threads). Thus, in addition to the tool for profiling the grinding wheel, a tool is required to adapt the tip diameter of the grinding wheel. The tip diameter is reduced until the tip area of the thread(s) of the grinding wheel has again assumed the originally provided width.
Thus, the means for dressing the grinding wheel usually comprises two separate tools. The tool for profiling the flanks of the grinding wheel may be a dressing disk, for example. The grinding wheel is generally not dressed with these two tools at the location on the machine where the work piece, i.e., the gear wheel, is later machined. However, for reasons of precision, it is desired to perform the dressing process at the location where the grinding wheel subsequently machines the work pieces. Therefore, it has already been proposed (German patent application 102 20 513.2) to use an essentially cylindrical gear wheel to profile the flanks of a threaded grinding wheel. The gear wheel has an abrasive coating on the surface that is active in the dressing and is incorporated on the work piece spindle of the machine in place of the work piece. Because the sole purpose of said gear wheel is to profile the flanks of the grinding wheel, an additional means is required for adapting the tip diameter of the grinding wheel.
A modification of this work method provides using an essentially cylindrical roll having an abrasive coating on its circumference for adapting the tip diameter of a grinding wheel, with the gear wheel and the roll being joinable to the work piece spindle of the machine in an axially fixed and non-rotatable fashion (German patent application 103 22 181.6). When the grinding wheel is brought into engagement with the cylindrical roll after the profiling of the flanks of the wheel to adapt the tip diameter, material is removed from the tip area of the thread or the threads of the grinding wheel. In this process, sharp edges are created at the transition of the tip area into the flanks of the wheel. However, the edges create undesired machining stages in the tooth flanks of the gear wheel (unsteady profile transitions in the tooth base area) when a gear wheel is ground with the grinding wheel profiled in said manner.
The invention is based on the problem of creating a dressing tool of the type mentioned earlier, which enables a profiling of the tip area of the thread (or the threads) of the grinding wheel with rounded edges.